Nuclear localization of prostaglandin E-2 receptors

Prostaglandin E-2 receptors (EP) were detected by radioligand binding in nu clear fractions isolated from porcine brain and myometrium. Intracellular l ocalization by immunocytofluorescence revealed perinuclear localization of EPs in porcine cerebral microvascular endothelial cells. Nuclear associatio n of EP1 was also found in fibroblast Swiss 3T3 cells stably overexpressing EP1 and in human embryonic kidney 293 (Epstein-Barr virus-encoded nuclear antigen) cells expressing EP1 fused to green fluorescent protein. High-reso lution immunostaining of EP1 revealed their presence in the nuclear envelop e of isolated (cultured) endothelial cells and in situ in brain (cortex) en dothelial cells and neurons. Stimulation of these nuclear receptors modulat e nuclear calcium and gene transcription.